The description herein relates generally to low density materials for incorporation into composite formulations, and more particularly, to an engineered material that provide very low moisture movement and methods of making such materials.
Composite materials, such as fiber cement, typically incorporate additives to enhance and/or modify material properties. For example, to reduce density, additives, especially porous additives, may be used as density modifiers to reduce the overall density of the composite material when fabricated or in a slurry. The low density property of such additives are, in part, attributed to their foamed, hollow or porous structure. However, pores within such structures do allow for water and moisture absorption as well as water retention and movement.